Işıl Aydemir

Effects of 5-fluorouracil and gemcitabine on a breast cancer cell line (MCF-7) via the JAK/STAT pathway.

Aberrant activation of the JAK/STAT pathway may predispose to malignancy as a consequence of the deregulation of cell proliferation, differentiation or apoptosis such as in cancer of the blood, head and neck, and breast. In our study we aimed to investigate the effects of 5-fluorouracil (5-FU) and gemcitabine on a breast cancer cell line (MCF-7 cells) via the JAK/STAT pathway. Distribution of JAK1, JAK2, JAK3 and STAT2, STAT3, STAT4, STAT5 were evaluated on MCF-7 cells following gemcitabine and 5-FU treatment and in the absence of drug treatment by an indirect immunohistochemical method. It was observed that JAK1, JAK3, STAT5 and particularly STAT2 activation were more effective than the other JAK/STATs in breast cancer progression. Following treatment with 5-FU, JAK1 and STAT5 immunoreactivities were decreased in MCF-7 cells in comparison with both gemcitabine-treated and non-treated groups. These results suggest that the JAK/STAT pathway plays an important role in breast cancer pathogenesis and may be more affected after 5-FU treatment rather than gemcitabine. Drugs which block STAT5 may provide a novel therapeutic approach for the treatment of breast cancer.

Histological investigations on thymus of male rats prenatally exposed to bisphenol A

Bisphenol A is called as a endocrine-distrupting chemical because of the its steroid-like activity and it used in the construction of plastic containing materials. It is indicated that bisphenol A can pass the human serum, urine, follicular fluid, placenta and umblical cord as a result of the use of substances containing this agent. In this study, we aimed to investigate the effects of bisphenol A on the development of the thymus, a primary lymphoid organ which plays an important role in the specific immunity. The adult pregnant female rats were administered orally with bisphenol A (for 21 days) and postnatal thymus samples were obtained on day 21, 45 and 90 and were performed for histochemical and immunohistochemical staining for CD3, CD4, CD8 and CD79a and TUNEL assay for the apoptotic cells. Evaluation of all groups, CD3, CD4, CD8 and CD79a stainings were decreased in the experimental groups compared with control group. The apoptotic cells were determined in the all groups on day 90 as a result of the thymus involution. It is noted that there was not any histological and morphological damages in the rats prenatally exposed the bisphenol A. The effect of the bisphenol A is unknown in the future, but there is no problem in the adult rats.

Compression of the effect of pulsed electromagnetic field and pulsed radio frequency energy on wound healing in rats

Delayed or not sufficiently good wound healing is a significant problem in medical treatment is needed to support in order to improve healing. Low frequency electromagnetic field (EMF) applications are seems to give this support. Disturbed vascularization, connective tissue formation, matrix exchange, and inflammation process in the wound environment are modified after EMF applications compared with control groups. Deteriorations in these factors which can be returned with the electrical impulses, DNA synthesis, transcription and transforms of protein synthesis, increasing of fibroblasts and endothelial cell proliferation indicate the presence of EMF mechanisms. Since the application and ambient conditions are kept constant but the type of the application has been changed in our study, it was provided that pulsed radio frequency energy (PRFE) is more effective and has more long-term improvement compared to pulsed electromagnetic fields (PEMF). The effects of these applications on cells and understanding of the mechanisms of the behavior will be much more significant and meaningful contribute to the treatment.

Design of coils driven by pulsed electromagnetic field generator and the effect of wound healing in rats

Chronic wound healing is an important problem especially in diabetic and the elderly which is needed development of the current treatment methods. Electromagnetic fields (EMF) has a significant impact on our body. These fields are being used for bone problems, cartilage regeneration, and pain removal for physiotherapy purposes. Lately, EMFs are often used in in vitro and in vivo assays. In this study, in vivo test results of the applied pulsed electromagnetic fields (PEMF) with our designed Helmholtz coil array system are given. The skin wound healing conducted in rats as an experimental model provides important information for evaluating the efficacy and mechanism of these kind of treatments. For this purpose, effectiveness of PEMF compared to control groups on experimental skin healing effect was examined macroscopically. Compared with the control groups a faster wound healing process was followed by PEMF application at 75 Hz frequency.

Anatomy of stem cells

Human embryonic stem cells are important for the understanding of biologic mechanisms and their potential for treatment, and for toxicology studies. Mesenchymal stem cells can produce a good environment with chemical factors and signals to serve as anti-apoptotic, immune modulator and angiogenic, and can support regeneration in damaged tissues and induce faster and better wound healing. Stem cells have recently been shown in cancer tissue; these play a major role in the progression of cancer and the principal obstacle in treatment due to their resistance. Stem cells may participate in tissue homeostasis and regeneration which shows their capacity for cell therapies which makes them an amazing source for the clinical translation to treatment of diseases. Therefore, better understanding of the behavior of these cells and the mechanisms they use are important. Keywords: cancer; embryonic; hematopoietic; mesenchymal; pluripotent; stem cell